Inflatable airbag devices, which are more commonly referred to in the art as Supplementary Restraint Systems (SRS), Air Cushion Restraint Systems (ACRS), or Supplemental Inflatable Restraint (SIR) Systems, are originally equipped in almost all present day automotive vehicles. Included as part of an overall occupant restraint system, airbag devices are generally located in the vehicle passenger compartment, and act as a selectively deployable cushion capable of attenuating occupant kinetic energy. Moreover, airbags are designed to minimize inadvertent movement of the driver and/or other occupants to help avoid involuntary contact with interior portions of the automobile.
Traditional airbag devices comprise an inflatable airbag module stored behind the vehicle instrument panel (e.g., for passenger-side airbags), or mounted to the steering wheel hub (e.g., for driver-side airbags). A plurality of sensors or similar devices is strategically located throughout the vehicle to detect the onset of a predetermined activation event. The sensor(s) responsively activates an inflation device, internally located in the airbag module, to produce a flow of inflating gas into an inflatable flexible membrane (i.e., an airbag cushion), which is normally folded inside of the airbag module. This causes the airbag cushion to deploy in a rearward direction within the vehicle passenger compartment.
Most passenger-side SIR systems are disposed within and behind the instrument panel, which extends across the width of the vehicle's passenger compartment, at the forward most end thereof. The instrument panel may utilize a deployment door (e.g., visible door) to cover an opening formed in the instrument panel for the airbag cushion to deploy through. The discrete airbag door is designed to open in response to the force of the expanding airbag cushion. That is, as the pressure in the airbag cushion increases, a force is generated along an underside surface of the discrete door. At least a portion of the door then selectively separates from the remaining portion of the instrument panel to permit the airbag cushion to deploy through the opening in the instrument panel, into the vehicle passenger compartment.
Generally, a vehicle instrument panel comprises a plurality of layers, which may include a rigid substrate, an aesthetic cover, and an optional foam layer therebetween. Conventional methods of manufacturing a vehicle instrument panel involve multiple separate forming and manufacturing process steps depending upon the instrument panel construction required. First the instrument panel is formed to accommodate, among other things, the size and shape of the SIR system. In the interim, the discrete door is formed in a separate process. Finally, the discrete door is assembled onto the instrument panel for use in conjunction with the SIR system. The steps involved in the manufacture of a conventional instrument panel consume substantial time and resources, and result in an aesthetically apparent (e.g., visible) airbag door.